1. Field of the Invention
The present invention relates to novel fluorinated dendrons and to a method for producing functional fluorinated dendrons programmed to self-assemble into supramolecular nanocylinder compositions containing p-stacks of high electron or hole mobility donors (D), acceptors (A), or D-A complexes in the core. Such nanocylinder compositions are uniquely useful in devices such as transistors, photovoltaics, photoconductors, photorefractives, light emissives, and optoelectronics.
2. Background
Self-organized organic nanostructures with controlled optoelectronic properties that facilitate ultrahigh density nanopatterning have been attempted to be developed for molecular electronics. In this regard, charge carrier mobility (xcexc) in organic materials appears to be mediated by p-stacking of conjugated groups, a principle resembling that of base pairs in DNA. Examples are disc- and rod-like molecules stacked in discotic hexagonal and calamitic liquid crystals (LCs), and acenes in single crystals. The development of these structures has required the synthesis of novel complex molecules and the elaboration of new processing techniques for LCs and single crystals.
The discovery of the first organic conducting polymer, polyacetylene, initiated early work relating to molecular optoelectronics. However, further work has required the development of new organic systems that exhibit higher processability, efficiency, xcexc, density of active elements per square centimeter, mechanical integrity, and lower costs than inorganic analogues. For example, amorphous organic polymers like poly(-vinyl-carbazole) have good mechanical properties, but their xcexc is very low (10xe2x88x928-10xe2x88x926 cm2xc2x7Vxe2x88x921xc2x7sxe2x88x921). Single crystals have high xcexc (10xe2x88x921 cm2xc2x7Vxe2x88x921xc2x7sxe2x88x921) but are difficult to fabricate. In 1994, discotic hexagonal LCs based on aromatic molecules such as triphenylene were shown to exhibit u approaching those of single crystals. However, their effectiveness has been hindered by the multistep synthesis of each disc, their different phase behavior, and their complex processability.
The general state of the art relating to dendritic polymers and their uses, and compounds having electron-accepting or electron-donating systems, is described in the following U.S. Patents.
U.S. Pat. No. 5,731,095 to Milco, et al., issued Mar. 24, 1998, discloses water-soluble or water-dispersible fluorine-containing dendritic polymer surfactants.
U.S. Pat. No. 5,872,255 to Attias, et al. issued Feb. 16, 1999, discloses conjugated compounds having electron-withdrawing or electron-donating systems, and the use of said compounds or of any material which includes them in electronic, optoelectronic, nonlinear optical, and electrooptical devices.
U.S. Pat. No. 5,886,110 to Gozzini, et al. issued Mar. 23, 1999, discloses branched, dendrimeric macromolecules having a central nucleus and a series of polyoxaalkylene chains that radiate from the nucleus and spread into the surrounding space, branching in a cascade fashion until the desired size results.
U.S. Pat. No. 6,020,457 to Klimash, et al. issued Feb. 1, 2000, discloses dendritic polymers containing disulfide functional groups which are essentially inert under non-reducing conditions, but which form sulfhydryl groups upon being subjected to a reducing agent, and their uses in the formation of differentiated dendrimers, formation of binding reagents for diagnostics, drug delivery, gene therapy and magnetic resins imaging, and in the preparation of self-assembled dendrimer monolayers on quartz crystal resonators to provide dendrimer-modified electrodes which are useful for detecting various ions or molecules.
U.S. Pat. No. 6,051,669 to Attias, et al., issued Apr. 18, 2000, discloses conjugated polymer compounds having electron-withdrawing or electron-donating systems, and the use of said compounds or of any material which includes them in electronic, optoelectronic, nonlinear optical, and electrooptical devices.
U.S. Pat. No. 6,077,500 to Dvornic, et al., issued Jun. 20, 2000, discloses higher generation radially layered copolymeric dendrimers having a hydrophilic poly(amidoamine) or a hydrophilic poly(propyleneimine) interior and a hydrophobic organosilicon exterior, and their uses for delivering active species for use in catalysis, pharmaceutical applications, drug delivery, gene therapy, personal care, and agricultural products.
U.S. Pat. No. 6,136,921 to Hsieh, et al., issued Oct. 24, 2000, discloses a coupled polymer which is prepared by reacting a living alkali metal-terminated polymer with a coupling agent, having good rubbery physical properties, transparency, and wear resistance.
U.S. Pat. No. 6,312,809 to Crooks, et al., issued Nov. 6, 2001, discloses a substrate having a dendrimer monolayer film covalently bonded to the surface, and uses as a chemically sensitive surface, such as in chemical sensors.
The prior art has been ineffective in formulating effective structures that have higher processability, efficiency, xcexc, density of active elements per square centimeter, mechanical integrity, and lower costs than inorganic analogues. Surprisingly, the present inventive subject matter overcomes these deficiencies in the prior art and is directed to the production of novel functional fluorinated dendrons which are programmed to self-assemble into supramolecular nanocylinder compositions containing p-stacks of high electron (xcexce) or hole (xcexch) mobility donors (D), acceptors (A), or D-A complexes in the core. The co-assembly of D- or A-dendrons with amorphous polymers containing A or D side groups, respectively, incorporates the polymer backbone in the center of the cylinder via p-stacks of D-A interactions and enhances u of the resulting polymer. These supramolecular cylinders self-process into homeotropically aligned hexagonal and rectangular columnar LCs that pattern ultrahigh density arrays (up to 4.5xc3x971012 cylinders per square centimeter) between electrodes. Below glass transition temperature, a complex and organized optoelectronic matter of cylinders composed of helical dendrons jacketing stacks of aromatic groups with even higher, essentially insensitive to ionic impurities, is produced. Such arrays are uniquely applicable to devices having a broad range of sizes. In particular, such compositions are used in devices spanning the range from single supramolecule, to nanoscopic, to macroscopic. Useful devices for including said compositions are transistors, photovoltaics, photoconductors, photorefractives, light emissives, and optoelectronics, which has not heretofore been possible.
The present invention relates to a compound of formula I 
wherein:
X is Zxe2x80x94(CH2CH2O)n, where n is 1-6, or Zxe2x80x94(CH2)mO, where m is 1-9;
Y is selected from the group consisting of pentalene, indene, naphthalene, azulene, heptalene, biphenylene, indacene, acenaphthylene, fluorene, phenalene, phenanthrene, anthrcene, fluoranthene, acephenanthrylene, aceanthrylene, triphenylene, pyrene, chrysene, and naphthacene,
wherein said Y is optionally substituted with 1-6 substituents selected from the group consisting of nitro, nitroso, carbonyl, carboxy, oxo, hydroxy, fluoro, perfluoro, chloro, perchloro, bromo, perbromo, phospho, phosphono, phosphinyl, sulfo, sulfonyl, sulfinyl, trifluoromethyl, trifluoromethylsulfonyl, and trimethylsulfonyl,
and wherein 1-4 carbon atom(s) of said Y is/are optionally replaced by N, NH, O, or S; and
Z is selected from the group consisting of a direct bond, xe2x80x94C(O)Oxe2x80x94, (C1-C6 alkyl)xe2x80x94C(O)Oxe2x80x94, (C2-C6 alkenyl)xe2x80x94C(O)Oxe2x80x94, and (C2-C6 alkynyl)xe2x80x94C(O)Oxe2x80x94.
The present invention further relates to a process for making a stacked nanocylinder composition having a mobility donor complex, a mobility acceptor complex, or a mobility donor-acceptor complex in its core, which comprises:
(a) heating semi-fluorinated dendrons incorporating selected dendron apex moiety(ies) and side group(s) having donor, acceptor, or donor-acceptor characteristics to an isotropic phase temperature;
(b) filling a substrate with said isotropic phase dendrons; and
(c) cooling said dendrons to a liquid crystalline phase temperature.
The present invention further relates to the stacked nanocylinder composition described above, made by the process which comprises the steps of:
(a) heating semi-fluorinated dendrons incorporating selected dendron apex moiety(ies) and side group(s) having donor, acceptor, or donor-acceptor characteristics to an isotropic phase temperature;
(b) filling an indium tin oxide coated glass substrate with said isotropic phase dendrons; and
(c) cooling said dendrons to a liquid crystalline phase temperature at a rate of about 0.1xc2x0 C. per minute, in the presence of a magnetic field of about 1 tesla.